598 research outputs found

    Leaf Mining Insects and Their Parasitoids in the Old-Growth Forest of the Huron Mountains

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    Leaf mining insects in an old-growth forest along the south central shore of Lake Superior in Michigan are documented. We present the results of a 13-year survey of leaf mining species, larval hosts, seasonal occurrence, and parasitoids, as well as report biological observations. Representative larvae, mines, adults, and parasitoids were preserved. Among the larval host associations, 15 are reported as new. Additionally, 42 parasitoid taxa were identified resulting in six first reports from the New World and 32 new host associations. Two undescribed species (Gelechiidae and Figitidae) discovered through this research were described in earlier publications

    Comparison of Some Exact and Perturbative Results for a Supersymmetric SU(NcN_c) Gauge Theory

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    We consider vectorial, asymptotically free N=1{\cal N}=1 supersymmetric SU(NcN_c) gauge theories with NfN_f copies of massless chiral super fields in various representations and study how perturbative predictions for the lower boundary of the infrared conformal phase, as a function of NfN_f, compare with exact results. We make use of two-loop and three-loop calculations of the beta function and anomalous dimension of the quadratic chiral super field operator product for this purpose. The specific chiral superfield contents that we consider are NfN_f copies of (i) F+FˉF+\bar F, (ii) AdjAdj, (iii) S2+Sˉ2S_2+\bar S_2, and (iv) A2+Aˉ2A_2 + \bar A_2, where FF, AdjAdj, S2S_2, and A2A_2 denote, respectively, the fundamental, adjoint, and symmetric and antisymmetric rank-2 tensor representations. We find that perturbative results slightly overestimate the value of Nf,crN_{f,cr} relative to the respective exact results for these representations, i.e., slightly underestimate the interval in NfN_f for which the theory has infrared conformal behavior. Our results provide a measure of how closely perturbative calculations reproduce exact results for these theories.Comment: 16 pages, 3 figure

    Temporal Variability in Survival of Non-Breeding Northern Bobwhites in Ohio

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    Non-breeding season survival is an important determinant of population growth rates of northern bobwhites (Colinus virginianus) and is primarily influenced by hunter harvest, predation, and weather. The collective influence of these factors varies within and among years and across the bobwhite range. Understanding factors that influence variation in survival is important to inform regionally-specific management strategies for declining bobwhite populations. We radiomarked 311 bobwhites from 73 coveys to investigate temporal variation in non-breeding season (Oct-Mar) survival of a declining bobwhite population on private land in southwestern Ohio during 2008–2011. We used the data bootstrapping feature in Program MARK to adjust for overdispersion caused by dependency of survival among members of the same covey. Temporal variation in survival was best modeled (wi 1⁄4 0.935) with weekly differences in survival rates that varied within and between years. There was only slight dependency in survival due to covey affiliation between the 2 seasons (median cˆ 1⁄4 1.51). Non-breeding season survival was low (Sˆ 2009–2010 1⁄4 0.05, 95% CI 1⁄4 0.03-0.11, Sˆ 2010–2011 1⁄4 0.12, 95% CI 1⁄4 0.07- 0.20) in 2 years with data for the entire season. Survival during 10 December-31 March varied among the 3 years (Sˆ2008–2009 1⁄4 0.45, 95% CI 1⁄4 0.29-0.61, Sˆ2009–2010 1⁄4 0.11, 95% CI 1⁄4 0.05-0.21, Sˆ2010–2011 1⁄4 0.25, 95% CI 1⁄4 0.17-0.34). There were 2 periods of low survival; a short period in early fall that coincided with senescence of herbaceous vegetation and the hunting season, and during periods with prolonged snow cover during winter. Late winter survival during periods of snow cover was most variable and winter severity appeared to have the greatest influence on seasonal survival during our study. Management strategies to improve non-breeding season survival in northern populations should focus on managing winter habitat to improve survival during periods of prolonged snow cover

    Spring Dispersal of Northern Bobwhites in Southwestern Ohio

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    Northern bobwhites (Colinus virginianus) historically occurred throughout Ohio but their core range has contracted to 18 southwestern counties. The Ohio Division of Wildlife has used trapping and transplanting to reintroduce wild bobwhites to unoccupied habitats within the species’ historic range. Bobwhite dispersal information is necessary to understand population dynamics and the species’ capacity to recolonize unoccupied habitats. Bobwhites were captured and radiomarked on 4 private-land study sites in southwestern Ohio. Radio-marked bobwhites (n 1⁄4 66) were tracked by homing or triangulation during spring 2010 and 2011 to ascertain dispersal distances between winter and breeding ranges. The spring dispersal period was defined by break-up of coveys and subsequent occupation of breeding season home ranges. The dispersal period, defined by non-affiliation with coveys, long directional daily movements, and observed breeding activity, varied among individuals and ranged from 2 April to 26 May. Dispersal distances were measured as the net Euclidean distance between locations recorded at the beginning and end of the dispersal period. Dispersers were defined as birds that moved . 23 the diameter of the mean home-range size (26.1 ha) observed during October-March 2010 and 2011. Movements of 1–2 home-range diameters were classified as home range shifts. Non-dispersing bobwhites traveled , 1 home-range diameter. Mean movement for all birds was 1.54 km. Twenty-eight (42.4%) radio-marked bobwhites were non-dispersers, 15 (22.7%) shifted home ranges, and 23 (34.8%) dispersed. Non-dispersers moved a mean of 0.31 km (range 1⁄4 0.03–0.56 km), home range shifts averaged 0.78 km (range 1⁄4 0.60–0.99 km), and dispersers traveled a mean distance of 3.6 km (range 1⁄4 1.18–11.5 km). Dispersal distance was lowest for adult females and increased in order for adult males, juvenile females, and juvenile males. Dispersal distance decreased as the proportion of early successional wooded habitat within winter home ranges increased. Sex, age, and dispersal distance did not affect survival. Our results suggest Ohio bobwhites are capable of expanding their range into historically-populated areas

    Efficacy of Targeted Mist-Netting to Capture Northern Bobwhites During the Non-Breeding Season in Ohio

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    Baited funnel traps and nightlighting are well established northern bobwhite (Colinus virginianus) capture techniques, but their use is not always appropriate, particularly on private land where cooperating landowners may place constraints on research activities. Alternative capture techniques may be more effective under conditions considered to be unfavorable for established techniques (e.g., periods with abundant natural food). Targeted mist-netting, where mist nets are erected near the known location of specific individuals, has been used to capture gallinaceous species and may be an effective alternative to established bobwhite capture techniques. We evaluated the effectiveness of using targeted mist-netting to capture bobwhites during the non-breeding season in Ohio. We tested for differences in survival and age and sex ratios of individuals captured with targeted netting and baited funnel traps. We captured 257 individuals with targeted netting during 1 October-28 February 2009–2011 and concurrently captured 253 individuals with baited funnel traps. There was a short-term influence of capture and handling, but there was no significant difference in post-capture survival of bobwhites captured with targeted netting or trapping. Capture rates of age and sex classes were similar (P 1⁄4 0.488 and P 1⁄4 0.973, respectively) between targeted netting and trapping. Body mass of bobwhites captured by targeted netting was less than that of bobwhites captured by trapping (P 1⁄4 0.009) suggesting that netting may provide more accurate estimates of body mass. We used targeted netting to capture bobwhites in a variety of situations where use of funnel traps was ineffective or problematic. Targeted netting was effective and often more compatible with constraints of working on private land than established capture techniques

    Leaf Mining Insects and Their Parasitoids in the Old-Growth Forest of the Huron Mountains

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    Leaf mining insects in an old-growth forest along the south central shore of Lake Superior in Michigan are documented. We present the results of a 13-year survey of leaf mining species, larval hosts, seasonal occurrence, and parasitoids, as well as report biological observations. Representative larvae, mines, adults, and parasitoids were preserved. Among the larval host associations, 15 are reported as new. Additionally, 42 parasitoid taxa were identified resulting in six first reports from the New World and 32 new host associations. Two undescribed species (Gelechiidae and Figitidae) discovered through this research were described in earlier publications
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